Improvement in boiler-furnaces



UNITED STATES PATENT OFFICE.

JOHN A. T. OVEREND, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT IN BOILER-FURNACES.

Specication forming part of Letters Patent No. 102,581, dated May 3,1870 antedated April 23, 1870.

To all whom it may concern Be it known that I, JOHN A. T. OVEREND, ofSan Francisco, in the county of San Francisco and State of California,have invented a new and useful Improvement in Boiler-Furnaces; and I dohereby declare that the following is a full, clear, and exactdescription thereof', which will enable others skilled in the art tomake and use the same, reference being had to the accompanying drawings,forming part of this specitication.

The object of this invention is to provide improvements in theconstruction ot' bridgewalls and furnace-backs for boiler-furnaces,calculated to make them more durable and to facilitate repairs.

The invention consists in theapplication, to furnaces, of metallicfire-backs and bridgewalls, arranged for ready removal for thesubstitution of others when worn out, and in a manner calculated toresist the heat to the best advantage, and to provide an air-chamberbehind the bridge-wall to facilitate the combustion of the gases, all ashereinafter more fully specified.

Figure l represents a longitudinal section of my improvement, and Fig. 2represents a front elevation of the same.

Similar letters of reference indicate corresponding parts.

A represents a base-plate, of metal, supporting a bridge-Wall, B, havinga shoulder, C, for the support of the removable fire-back D,

also of metal. and supporting at the rear a wall, E, which forms therear of an air-space, F, behind the bridge-wall. The front part G of theplate A also supports the rear of the tire-grate.

These parts are commonly made of brick, and soon crumble and wear away,and are difficult to replace. Y f

My object in the construction and arrangement of them in this way is t0make them more durable and more ready of removal, which may be done inthe case of either part by lifting the one o' and putting in place thenew ones.

Air may be caused to circulate through the space F for the protection ofthe lire-back D, and air may be supplied in any Way to the chamber Gbehind the bridge-wall for the protection of the latter, and forsupplying oxygen to the gases to cause them to be more fully consumed inthe space beyond'.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- The combination, in a boiler-furnace, ot' themetallic plate A, bridge-Wall B, Wall E, and fire-back D, when arrangedsubstantially as specified.

J. A. T. OVEREND.

Witnesses:

WM. W. DUNN, EDWARD C. BROWN.

